POOL FIRES OF BIOFUELS AND THEIR BLENDS WITH PETROLEUM DIESEL

The combustion characteristics of pool fires of biofuels, canola methyl ester (CME), soy methyl ester (SME), and their blends with a petroleum fuel (No. 2 diesel) were studied. The fuels were burned in cups of two sizes (0.042 m and 0.057 m in diameter and 0.038 m height) that simulated convection-dominated small pool fires of liquids. Blends of CME and SME with diesel fuel were tested with biofuel concentrations of 25, 50, and 75% by volume. The mass burn rate, the fuel surface regression rate, the radiation emission from the flames, the flame temperature field, and the emission indices of CO and NOx were recorded. The fuel surface regression rate in both containers was comparable. Both the fuel mass burning rate and surface regression rate varied non-monotonically with the volume concentration of biofuel in the blend. The radiation fraction of heat release and the temperature profiles were similar for all the flames. The CO emission index decreased with the biofuel content in the fuel. The NOx emission index did not show a systematic and significant dependence on the fuel blend; however, it was smaller than that measured in the turbulent gas jet and liquid spray flames of the corresponding fuels.